浙北地区利用冬闲虾塘饲养日本对虾的试验

利用饲养南美白对虾的冬闲虾塘 ,采取精养模式养一茬日本对虾 ,可提高围塘养殖的综合效益。本试验的放养密度为 2× 10 4余尾 / 6 6 7m2 ,单产 38.5kg/ 6 6 7m2 ,成活率 2 3.3%。盐度控制在 17以上     

旱作春小麦籽粒形成与灌浆特性

为了给旱地春小麦高产栽培提供依据,对内蒙古赤峰林东旱作地区春小麦籽粒建成及灌浆特性进行了观察和分析。结果表明,籽粒体积和含水量呈单峰曲线变化,籽粒干物质积累量符合“S”型曲线变化。开花后13-27d是小麦籽粒灌浆直线增长阶段,籽粒含水量相对平稳,籽粒重量直线增长,此期干物质积累量的占粒重的78%,为小麦产量形成的关键时期;不同农艺栽培措施对籽粒形成具有显著影响,只有密度适宜,氯、磷、钾三要素适量配施,才能提高灌浆强度,促进籽粒体积增大,增加粒重,获得高产。     

不同品质类型冬小麦籽粒产量和品质性状对氮肥的响应

为了研究不同品质类型冬小麦籽粒产量和品质性状对氮肥水平和追氮时期的响应,以两个强筋品种济南17和PH82-2-2以及两个筋力弱的品种PH97-4和PH97-5为材料进行了品种、施氮量、施氮时期三因素试验。结果表明,增施氮肥能显著提高小麦产量和氮收获量。起身期追肥比抽稳期追肥产量和氮收获量显著提高;不同品质类型的小麦蛋白质含量对施氮量和追氮时期反应不尽一致,蛋白质含量相对较低的两个品种济南17和PH97-4施氮处理间差异不显著,而蛋白质含量相对较高的品种PH82-2-2和PH97-5在高施氮量下抽穗期追肥蛋白质含量比起身期追肥提高0．6个百分点,差异达显著水平。不同品种的湿面筋含量、籽粒容重和硬度在不同施氮量下差异不显著。沉淀值、降落值对施氮处理不敏感;吸水率和面团稳定时间不同施氮量间差异不显著,抽穗期追肥吸水率提高0．7个百分点,但面团形成时间和稳定时间分别降低1．39min和0．61min;不同品种的粉质特性差异显著。运筹氮肥能改善小麦加工品质,但效果不明显。     

宁夏灌区春小麦源库演变规律的研究

为探讨宁夏灌区春小麦品种更替过程中源库的演替规律,以宁夏灌区四次更新的主栽春小麦品种和搭配品种及近年来的重要育成品种为对象,分析了源库指标及产量的变化。结果表明,随着品种的更替,宁夏灌区春小麦的源强从1953年以前的35.66 μmol CO₂·m^-2·s^-1增加到了1995年以后的106.99 μmol CO₂·m^-2·s^-1,提高了3倍;库容由289.97 g·m^-2增加到554.18 g·m^-2,提高了1.91倍,经济系数从0.29增加到0.38。源库协同改良使得春小麦的产量逐年增加。生物产量的增加主要依赖于源指标的改善,而籽粒产量的增加需要改善源库综合指标。因此,实现宁夏灌区春小麦产量的突破,应在增库的基础上扩源,建立合理的群体,协调源库比,促进春小麦光合产物向库的运转。     

垄作栽培对冬小麦根系活力和旗叶衰老的影响

为了明确垄作栽培条件下冬小麦根系活力与旗叶衰老的变化规律,采用垄作种植方式与传统平作栽培相比较的方法,研究了2种不同种植方式对2个小麦品种烟农19和济麦19根系活力及旗叶衰老的影响。结果表明,垄作栽培中由于小麦种植在垄顶上,0-60 cm土层根系干重较平作栽培增加12％以上,深层土壤(20-60 cm)根系活力得到极显著提高。在垄作栽培条件下,小麦生育后期旗叶叶绿素含量和光合速率较传统平作均有显著提高。开花15 d后,垄作栽培条件下的SOD、CAT、POD活性及可溶性蛋白质含量等较传统平作栽培均有显著提高,MDA含量显著降低。垄作栽培与传统平作栽培在同等节水条件下有利于提高小麦深层根系活力,延缓旗叶衰老。     

基于临界氮浓度稀释曲线的小麦氮肥需求量估测研究

为探究基于临界氮浓度稀释曲线估测小麦氮素需求量的可行性,基于不同生态区开展的不同品种及氮肥水平的小麦试验,结合小麦临界氮浓度曲线(N_c=4.16W~(-0.41)),构建了拔节期、孕穗期、抽穗期和开花期四个关键生育时期下,小麦氮营养指数(NNI)、氮素需求量(NR)及相对产量(RY)三者间的关系模型,并进行了验证。结果表明,在江苏地区,当总施氮量在120～180kg·hm~(-2)时,小麦的氮素需求量最接近于0,氮营养指数最接近于1,为最优的氮素施用量。氮营养指数与氮素需求量(NNI-NR)在小麦生长的各关键阶段存在极强的线性关系(R~2=0.93～0.97);相对产量与氮营养指数(RY-NNI)在各生育时期呈现线性加平台关系,在开花期表现最好,R~2=0.86;相对产量与氮素需求量(RY-NR)的拟合关系在抽穗期表现最好,R~2值为0.72。NNI-NR验证结果与建模结果一致,即在各时期均表现良好,其中拔节期相关关系最强;但RY-NNI和RY-NR验证结果显示两模型分别在开花期和抽穗期预测效果表现最佳。综上,所构建的NNI-NR、RY-NNI和RY-NR三种模型均具有良好的拟合优度和稳定性,运用基于临界氮浓度曲线的小麦氮营养指数和确立的相对产量水平,可以较好地估测当季的小麦氮素需求量,并进行小麦田间氮素精确管理。     

Optimization of Bread Preparation from Wheat Flour and Malted Rice Flour

The feasibility of partially replacing wheat flour with malted rice flour in bread making was evaluated in several formulations, aiming to find a formulation for the production of malted rice-wheat bread with better nutritional quality and consumer acceptance. The whole grains of a local rice variety (Oryza sativa L. subsp. indica var. Mottaikaruppan) were steeped in distilled water (12 h, 30°C) and germinated for 3 days to obtain high content of soluble materials and amylase activity in bread making. The quality of bread was evaluated by considering the physical and sensorial parameters. When the wheat flour was substituted with malted rice flour, 35% substitution level and the malted rice flour from 3 days of germination was the best according to the physical and sensory qualities of bread. The quality of bread was improved by the addition of 20 g of margarine, 20 g of baking powder and 20 g of yeast in 1 kg of flour. Among different ratios of yeast and baking powder, 2:1 was the best. Bread improver containing amylases and oxidizing agents at the concentration of 40 g/kg was selected as the best concentration. When comparing the final formulation made in the bakery with wheat bread, malted rice-wheat bread contains more soluble dietary fiber (0.62%), insoluble dietary fiber (3.95%), total dietary fiber (4.57%) and free amino acid content (0.64 g/kg) than those in wheat bread (0.5%, 2.73%, 3.23% and 0.36 g/kg, respectively).     

Effects of Irrigation and Straw Mulching on Microclimate Characteristics and Water Use Efficiency of Winter Wheat in North Chinas

Abstract

In North China, irrigation is required to obtain a high yield from winter wheat; this results in rapid aquifer depletion. The primary objective of this study was to investigate the influencing mechanisms of irrigation and straw mulching in preserving the soil moisture. Maize straw (3?5 cm) was mulched immediately after sowing winter wheat, and irrigation water was supplied at 60 mm, controlled by using a flow meter, during the jointing, heading, or milking stages of the crop. The results revealed that irrigation decreased the eddy thermal diffusivity, sensible heat flux, and soil heat flux, but increased the latent heat flux. In contrast, straw mulching enhanced the eddy thermal diffusivity and sensible heat flux, but decreased the latent heat flux. Straw mulching increased the soil temperature at 5 cm depth form January to February, but decreased the soil temperature before January and after February. There were no significant differences in the total evapotranspiration between mulched and non-mulched treatments, however, there was a statistically significant difference in the evapotranspiration among the different growing seasons. Straw mulching reduced the evapotranspiration from the seeding stage to the regrowing stage, and the evapotranspiration with mulching was less than that non-mulching 47.4 mm. Further, straw mulching significantly reduced the number of spikes in the crop. Both irrigation and straw mulching increased the number of kernels, but had no visible effects on the thousand kernel weight. These results indicate that straw mulching may decrease the yield and water use efficiency (WUE) of winter wheat in North China.     

基于适宜尺度选择的冬小麦赤霉病遥感监测

为快速、准确获取江淮麦区县域冬小麦赤霉病发生信息,选用中、高空间分辨率卫星遥感影像做多尺度信息融合研究。在筛选适宜冬小麦田块分布特征的空间尺度遥感影像基础上,通过分析冬小麦长势指标和赤霉病病情指数之间的互作关系,构建基于多农学参数的冬小麦赤霉病估测模型,并对县域冬小麦赤霉病空间变化进行遥感监测。结果表明:(1)2m×2m、8m×8m和16m×16m三种空间尺度融合影像的均值相差不大,平均梯度和标准差存在明显差异。16m×16m融合影像的清晰度最好,信息量也多,比较适合研究区域冬小麦田块分布特征。(2)16m×16m融合影像提取的归一化植被指数(NDVI)和比值植被指数(RVI)值明显高于2m×2m和8m×8m融合影像,说明16m×16m融合影像光谱信息量较丰富,有利于冬小麦的识别。(3)冬小麦叶面积指数、叶片叶绿素含量和地上部生物量是影响赤霉病发生的主要长势指标。基于主要长势指标构建冬小麦赤霉病估测模型,平方根误差(REMS)为10.5%,相对误差为14.6%。该方法可以实现对县域冬小麦赤霉病空间变化的有效监测。     

基于盐胁迫的小麦农艺性状多样性分析及评价

为筛选耐盐性优良的小麦资源,在0、0.3%和0.5%NaCl处理下,对黄淮麦区的132个小麦品种的8个数量性状进行了遗传多样性、相关性、主成分分析和耐盐性评价。结果表明,供试材料具有丰富的遗传多样性,且随盐浓度的升高,被测指标的变异系数和遗传多样性指数逐渐增大,其中单株成穗数、穗下茎节长和单株产量的变异系数均大于10%;除株高外,其他性状的遗传多样性指数均大于2。相关分析表明,在高盐(0.5%NaCl)胁迫下,株高与单株产量极显著正相关,而在低盐(0.3%NaCl)胁迫下则相关不显著;在低盐胁迫下,千粒重与单株产量极显著正相关,而在高盐胁迫下相关性不显著。主成分分析表明,在低盐、高盐胁迫下,前4个主成分累计贡献率达到82.677%、88.897%。以综合耐盐指数为依据,发现河北省的衡4399、石麦15,山东省的青麦6号、青丰1号、青农2号和烟农5286,河南省的洛旱6号、郑麦366、周麦22号、周麦23号和周麦28号共11个品种在两种盐分条件下均表现为耐盐性强。结合田间群体表现和产量,认为周麦22号、洛旱6号、郑366、青农2号、烟5286和衡4399为高产耐盐小麦种质资源,可在耐盐育种工作中加以利用。